South Africa's elite police unit today arrested three people as they raided the posh home of India-born Guptas, a controversial business family linked to embattled President Jacob Zuma, who is under pressure to quit.

According to a statement released by the Hawks - the police's elite high-priority crimes unit - the raids were carried out at the home of the Gupta family in the plush suburb of Saxonwold here in connection with the Vrede farm investigation.

Three people were arrested during the raid, with two more expected to surrender. According to local media reports, one of those arrested was a Gupta family member.

The embattled Gupta family own a range of business interests in South Africa, including computing, mining, air travel, energy, technology and media.

The three brothers, Atul, Rajesh and Ajay, moved to South Africa in 1993 from India, just as white-minority rule was ending.

They are known friends of 75-year-old President Zuma - and his son, daughter and one of the president's wives worked for the family's firms, media reports said.

The Gupta brothers have been accused of wielding enormous political influence in South Africa, with critics alleging that they have tried to "capture the state" to advance their own business interests.

The Vrede farm investigation relates to the Estina dairy farm near Vrede, in the Free State, a project which was originally meant to help poor black farmers but from which the Gupta family are alleged to have pocketed millions of dollars, allegations they deny.

Meanwhile, the African National Congress (ANC) party has given Zuma until the end of the day to resign.

His links to the Guptas are one of the reasons he is being forced to resign before the 2019 general election.

The Guptas and Zuma have denied all allegations of wrongdoing.

Pressure has been mounting on Zuma to quit in recent weeks. He was expected to respond to a formal request from the party to step down at some point on Wednesday.

However, the situation has escalated, with ANC chief whip Jackson Mthembu saying a motion of no-confidence in the president will be heard tomorrow.

Parliament will then elect Cyril Ramaphosa as the new president, potentially also tomorrow if the chief justice is available to swear him in, media reports said.